I'd like to hear how the 21.5" models with 500gb drive and 9400m are doing. From what I can gather, from speaking to a couple of people who have one, this is not showing the problems reported here by owners of the 27". If you have the iMac with 21.5" with 500gb drive, could you tell us what brand of drive is fitted, and if it is very quiet (no Seagate !T "grumbling" for example)? Also, if you've encountered any screen problems etc.